6月6日，著名学术杂志MOL. CELL. PROTEOMICS发表了北京大学生命科学学院蛋白质工程及植物基因工程国家重点实验室朱玉贤课题组研究棉纤维伸长机制的论文。他们通过比较野生型和无长绒、无短绒突变体棉花胚珠的蛋白质组学数据发现，核苷糖合成途径在棉纤维快速伸长期最显着高调，而植物激素乙烯可能通过促进植物细胞初生壁中果胶的生物合成来调控纤维等具有线性伸长机制的细胞生长。
这是他们继2006年发现乙烯在棉花纤维细胞伸长过程中的主导作用（Shi et al, Plant Cell 18: 651-664），2007年发现超长链脂肪酸位于乙烯信号上游，在转录水平调控乙烯生物合成，从而影响棉纤维伸长（Qin et al, Plant Cell 19: 3692-3704）后，有关棉花等线性伸长细胞生长发育机制研究中的又一重要贡献。(生物谷Bioon.com)
生物谷推荐原文出处：
MOL.CELL.PROTEOMICS doi: 10.1074/mcp.M110.000349
Comparative proteomics indicate that biosynthesis of pectic precursors is important for cotton fiber and Arabidopsis root hair elongation
Chao-You Pang1, Hui Wang2, Yu Pang2, Chao Xu2, Yue Jiao2, Yong-Mei Qin2, Tamara L. Western3, Shu-Xun Yu4 and Yu-Xian Zhu5,*
The quality of cotton fiber is determined by its final length and strength, which is a function of primary and secondary cell wall deposition. Using a comparative proteomics approach, we identified 104 proteins from cotton ovules 10 days post-anthesis, with 93 preferentially accumulated in the wild-type and 11 accumulated in the fuzzless-lintless mutant. Bioinformatics analysis indicated that nucleotide sugar metabolism was the most significantly up-regulated biochemical process during fiber elongation. Seven protein spots potentially involved in pectic cell wall polysaccharide biosynthesis were specifically accumulated in wild-type samples at both the protein and transcript levels. Protein and mRNA expression of these genes increased when either ethylene or lignoceric acid (C24:0) was added to the culture medium, suggesting that these compounds may promote fiber elongation by modulating the production of cell wall polymers. Quantitative analysis revealed that fiber primary cell walls contained significantly higher amounts of pectin, whereas more hemicellulose was found in ovule samples. Significant fiber growth was observed when UDP-Rha, UDP-GalA or UDP-GlcA, all of which were readily incorporated into the pectin fraction of cell wall preparations, was added to the ovule culture medium. The short root hairs of Arabidopsis uer1-1 and gae6-1 mutants were complemented either by genetic transformation of the respective cotton cDNA or by adding a specific pectin precursor to the growth medium. When two pectin precursors, produced by either UDP-4-keto-6-deoxy-D-glucose 3,5-epimerase 4-reductase or by UDP-D-glucose dehydrogenase and UDP-D-glucuronic acid 4-epimerase successively, were used in the chemical complementation assay, wild-type root hair lengths were observed in both cut1 and ein2-5 Arabidopsis seedlings, which showed defects in C24:0 biosynthesis or ethylene signaling, respectively. Our results suggest that ethylene and C24:0 may promote cotton fiber and Arabidopsis root hair growth by activating the pectin biosynthesis network, especially UDP-Rha and UDP-GalA synthesis.
